Record controlled printing apparatus



July 26, 1949.

J. A. SKINNER RECORD CONTROLLED PRINTING APPARATUS Filed March 26, 1945 6 Sheets-Sheet 1 O0 OO O O OO OO O O O O 0000 O O O JOHN A. S/f/A/A/ER 0 OOO O O O O 000 0 oo o 0000 000 000 O OOOOOOOOOOOOOOOOO 0000 o o oo oo o oo oo 00 000 00 000 lnkOk I l O I. 9 4 2 an a 2 a 4 s e 1 a s 0 O O O 0 00000 00 A B C D E F 6H1 JK L MN 0 P 0 RS T U VWX Y Z a b c d e f g in ij k 6 mroyqrs t u vwx 5} O OO INVENTOR ATTORNEa J. A. SKINNER RECORD CONTROLLED PRINTING APPARATUS July 26, 1949.

6 Sheets-Sheet 2 Filed March 26, 1.945

nu mm 0N W0 0 kn t l INVENTOR JOHN A. 5K/N/VER B Y Q L ATTORNEY y 26, 1949. J. A; SKINNER 2 477,011

RECORD CONTROLLED PRINTING APPARATUS Filed March 26, l945 6 Sheets-Sheet 3 FIGS. 22 m /03 I f v 4 4 FIG7.

INVENTOR JOHN I A. S/f/N/Vf/P ATTORNEY July 26, 1949. J. A. SKINNER RECORD CONTROLLED PRINTING APPARATUS Filed March 26, 1945 6 Sheets-Sheet 4 FIG.11.

INVENTOR JOHN A. SAV/V/VE/P ATTO R N EY July 26, 1949.

.s. A. SKINNER RECORD CONTROLLED PRINTING APPARATUS 6 Sheets-Sheet 5 Filed March 26, 1945 INVENTOR A. Jmnwse ATTORNEY y 6, 1949. J. A. SKINNER 2,477,011

RECORD CONTROLLED PRINTING APPARATUS Filed March 26, 1945 6 Sheets-Sheet 6 FIGJZ b.

$4671 SPA CE 7 7 6AA". R67. 7'24 745 252 7 INVENTOR JOHN .4. .S/r/N/VER BY WAC-$3 Patented July 26, 1949 UNITED STATES PATENT o-Fric-E;

RECORD. CONTROLLED PRINTING APPARATUS {Granted under; the act of- March 3,, 1.883,, as amended April 30; 1928,; 3.70 Oiv G. 75.7),

1-0. Claims;

This invention relates to. cyclically operable apparatusv and more particularly to record-con.- trolled printing apparatus. and it has: for a, general' object to provide apparatus of this type which. is of improved construction and arrangement of. parts and one which operates. in. an effective and dependable manner.

According to one of its aspects, the present invention may be. considered as being in. the nature of an improvement over th apparatus: dis.- closed in the copending application. of Henry L. Tholstrup, Serial No. 4592;896; filed June 30, 19.43, which has matured: into Patent No. 2,378,311, dated June 12, 1945.. As will appear more fully hereinafter, the. illustrative embodiment of the present invention includes asa part. thereof the same apparatus as is:dis c1osed.in said patent.

A. record-controlled printing;- apparatus of the type referred. toabove usually comprises. a reader, a typewriter, and control: instrumentalit-ies, which function to effect automatic operation of the typewriter inv accordance with. data recorded as code designationson a record strip and analyzed or sensed. by thereader. In recording the code designations. on the record strip of the data. to be: printed, code designations representing the required functional operations of the typewriter, such as space, back space, carriage return, tab.- ulating, etc, are: also recorded; Normally, the reader operates at, its designed. maximum speed in successive cycles and during each such cycle the record strip is spaced to bring a. recording field in the strip into sensing position, a code designation occupying, such field is sensed, and, in response to the latter, thev key lever off the typewriter corresponding to the character or functional operation represented by the sensed code designation, is actuated to effect the printing of such character or to effect such functional operation.

In said copending application, provision, is made for stopping the operation of the reader when a code designation is sensed that represents a typewriter functional operation requiring a longer time to be effected than is normally required to efiect a simple typing operation, and provision is made for resuming the reading operation at maximum speed when such functional operation is completed. The reader includes an operating shaft, usually referred to as the reader shaft, and which is. connectable by a suitable clutch to a suitable power shaft, the latter operating continuously ata designed, maximum speed, and when it is desired tov stop the reader operation momentarily, as, in the case just mentioned,

the clutch is operated to disconnect the reader shaft from the; power, shaft. For conventional letter writin on r a. he-a a a us iust. described operates efiectively, to; transcribe re.-

Y orded. data on. a. com; she t. ata high rate of speed. Apparatus of this.typeahoweyenissomer times: used: to control, or in; coordination with, additional appar tus; wherein, functions; are; per,- formed during each; cycle which; are in addition to those performed; during: a; simple letter; Writing; operation; and. these; additional functionsrequire: a. longertime; for, their completion. than. is normally provided between successive; readin cycles; wherr character data.-

typed, One ex;- ample ofi application on the latter: type, is where the apparatus; in addition to transcribing on a copy sheet the datawhich is recorded as code designations on a first; tape; controlsat the sametime the operationof a recording apparatus to reproduce-the data recorded in the first tape; on a second 'record tape and'inthe same or in a; differentcode; Other applications requiring a longer time between successi ve readin and printing cycles than is necessary for a; simple letter writing application; will beapparent to those-skilled in thi's'art.

It is a. more. specific object of the present in:- vention to provide an improved form ofrecordicontrolled" printing apparatus which may beoperated' at the maximum designed speed; for normal printing operations which, at the: will or the operator, may be readilyadjustedinr a simple and eiiectivemannerto; operate at a predeterminedslowertimerate.

A still; further object,- is to provide. an. improved cyclically operable recordcontrolled printing apparatus whichv includes, as a part thereon, a time controlled means for; timing the successive. operations Qfsucl'r apparatus.

Qther objects, of the invention will, be. pointed out, in. the; following. description and claims and illustrated in the accompanying, drawings. which disclose, by way of example, the principle of the invention and. the. best, mode,. which, has been contemplated}. or. apply ng that n iple;

Inthe drawings:

Fig. l; isapl'anview showing generally the. units composing. one preferred cmbocfilnent of, the pres,- ent. invention;

Fig, 2, is an enlarged fraglnentaryv planv sec.- tional view showing, detail, the. mechanical working parts of; thereader, which form a com.- ponent. part. at the, preferred: embodiment. shown in. Fla. 1;v certain. of; the, parts. being, broken away Fig. is a fragmentary vertical section through the reader, the section being taken at right angles to Figs. 3 and 4 and being indicatedby the line 55onFig.2;

Fig. 6 is a fragmentary vertical sectional view taken on the line 8-6 of Fig. 2, and illus trating the clutch mechanism and its controlling magnet which function to connect the reader 'operat ing shaft with a source of power;

Fig. 7 is a fragmentaryvertical section taken on the line of Fig. 3fand'showing the code.

sensing pins of the reader andthe'manner in which each pin controls it s related sensing contacts? A: i'; I I 1 --Fig. 8-is a verticalffront elevation showing a unitary timing niechanism 'whichis mounted within the reader housing; Fig.9 is a verticalside elevation of the 'construction shown in Figf8;

Figs; 10and '11 arefdetail views showing, re-

spe'ctively,'in elevation,- two different timing cams V which may beused alternatively in the mechanism shown in'FigsB and 9;

Figs. 12a and 12b are two parts of an electrical 'wiring'diagram illustrating diagrammatically the various control instrumentalities of the apparatus and the'circuit wires connecting them; and Fig. 13.is'aiview showing a portion of a record tape. bearing all of the code hole designations of a preselected combinational hole code system. J

Before considering in detailthe construction and operation of. the illustrated embodiment of theinvention; it will be helpful to. consider first one practical ,example of apreselected combinational code Joy means of which the intelligence, suchfor example; as a letter which it is desiredtmtranscribe, can be recorded on a record strip-or-tape. -In Fig. 13, a'portion of a record tape Ill is shown, arid punchedin the tape are all of thecode hole designations of a combinational sixehole code. LThe' 'six odepositions are indicated at bothends of the tape In by the reference numerals l tolB, inclusive, .and 'eachcode designation is arranged ina vertical column or recording field, and opposite each field bearing a code. designation and at the lower edge of the tape, is placed the'particular character or typewriter function corresponding to. the code designationlinthat field. 'The smaller holes II at the center ofthe tape, In and within each. of the several recording. fields are for the purpose of feeding the tape lengthwiseduring the reading or sensing operation. The code hole. designationsv and the feed holes I] imay be punched in the tape byany suitable form of code perfora tor (not shown herein).

Asshown in plan in Fig. 1, the record controlledprinting apparatus forming theillustrative embodiment of thepresent invention comprises generally a tape reader I00 enclosed withinQasuitable housing l2, and a power operated typewriter 200. As will appear more fully hereinafter, the apparatus also includes certain mechanisms, devices, circuits, and other control instrumentalities which provide for the automatic operation of the typewriter under the control of the code designations inthe record tape in sensed by the reader; The housing 12 is shown in'Fig; 1

. 4 as broken away so as to disclose in plan a unitary timing mechanism 300 which, as will later appear, forms an important part of the present invention. The timing mechanism 300 is shown 5 in detail in Figs.8', 9, 10, and 11 and diagrammatically in Fig. 12a and will be described fully hereinafter. The other'co'ntrol devices, instrumentalities. etc., and their connecting circuit -wires are also shown diagrammatically in Figs.

12a and 12b. As will appear more fully hereinafter, these control instrumentalities are suitably mounted within the reader housing l2 and a on and under the typewriter 200. The circuit wires connecting the control instrumentalities mounted in the'reader I00 with those mounted on the typewriter 200 are suitably enclosed within a cable RT shownin Fig; 1. t

Asviewed in Fig. 1 the reader is provided across its lower side with a platform or tape table [3 across which the record tape I0 bearing the recorded intelligence is fed s'tep-i-by-s'tep .during the operation of the apparatus. Atape supplyspool I5 is suitably mountedat the right-hand side of the table l3 and. serves to support :the record tape 10 to be read and transcribed. A'second or tape storage spool 16' is provided at the. left of the table l3; and, as will later appear; is rot'ated V by a-fiexible belt l'lduring operation of the ap-' paratus, for the purpose. of 'windingthe' tape in reader. The sensing station is indicated at '20 and, as will appear more fully hereinafterfthe recording fields of the tape are successively sensed during successiveoperating cycles by sensingelemerits located at the. station 20. 1A removable gate 21 is provided at the-.sensi'ngf'stationfor properly positioning and holding the 'tape'with respect to the sensing. elements. Theltape" In is guided in itsmovement towardithesensing station by'a suitable guide .member 22;fixed to the top of the tape'table i3." r

At the right-handside of the reader ion as viewed in Fig.1, are provided'threejelectri'cal switches indicated, respectively, at '24. 25, and 26, As will appear more'fully hereinafter, the switch 24 is the power'switch and when closed, connects a convenient source of alternating cur rent with a motor for. driving the reader unit and with a motor for operating the typewriteri The reader motor is indicated bythe character RM in" Figs. 2 and 12d, and the typewrite'rrnotor by TM in Figj12b. The switch '25 is; the start switch'and when closed, starts the sensin'g and feeding ofthe tape and'theautomatically' controlled operation of the typewriter key members. The switch 26 is the stop switch and" when' closed instantly stops the feeding and 'sensingfof the tape and: the controlled" operation of thetypebar is indicated at 223 The typewriter 200jalso' includes a rotatable platen 219 mounted on a carriage 220 which supports,in the usual mannenja copy sheet,;indicatedat 22!, on which thedata recorded in the tape I0 is automatically typed.

thereon after it'leaves the sensing'stationoftthe It is: noted: at. this point that a. complete showing of the details of construction of: the typewriter 2,00: and: a. detailedzdescriptionl of the operation. of the. typewriter. have not been included herein as. they are not considered as. being essential to a complete. understanding of the present invention. fully shown and. described in. a number of U. S. Letters Patent, and it is also disclosed in the said copending application of Henry L. Tholstrup and reference may be had thereto for: a complete understanding of the details of. construction.

The typewriter 200 may be operated. manually in the usual manner by depressing the character and functional keys. Each key is mounted upon a. corresponding; key lever 228 which is moved downward when. its key is depressed to effect the typing of the corresponding character,. or to effect the corresponding functional operation of the typewriter, if the key be a functional key. As is well known, in the particular form of typewriter shown, the power for effecting the typing and functional operations is supplied by a power roller (not shown) which is continuously perated by the typewriter motor TM. The motor TM is not shown structurally herein as it is of a well known construction; but, as stated above, it appears diagrammatically in Fig. 12b. Those skilled in this art will readily understand that the depressing of each typewriter key efi'ects a driving connection between the power roller and mechanism for effecting the operation of the correspondin character type bar, or for effecting the corresponding functional operation of the typewriter if a functional key is. depressed.

In order that the typewriter may be operated automatically under thecontrol of the code designations in the record. tape being sensed. by the reader, a key actuating solenoid: 239 (see Fig. 12b) is operatively connected to each of the typewriter key levers 228-. When each solenoid becomes energized in a manner which will be described more fully hereinafter, such solenoid will pull down its corresponding key lever 228 to effect the corresponding operation of the, typewriter in the same manner as when the key is manually depressed. The solenoids 230 have not been shown in Fig. 1 because to do so would only confuse the-showing of other structure: therein. The solenoids 230 are. indicated. diagrammatically in Fig. 12b, and adjacent each solenoid 230' is a legend indicating the character or functional operation controlled by such solenoid. The solenoids are arranged in the same order as their corresponding keys on the keyboard. 2H] in Fig. 1.

At the lower and left-hand side of the typewriter 200 as viewed in Fig. 1,. is provided a power switchv 224 which, when closed, like. the power switch 24, connects a source of alternating current with boththe' typewriter and reader motors. At the lower and right-hand side of the typewriter is mounted a start switch. 225 and a stop switch 226 which function, respectively, the same as the-switches 25 and 26 onthe reader I00. Thus, the operation of the apparatus may be controlled from either the typewriter or from the reader. An insert switch 221 is also provided on the typewriter which, when open, prevents starting of the tape feeding and sensing mechanisms in the reader Hill and thereby eliminates control by the latter of the typewriter, so; that the typewriter keyboard 2|U' can be operated manually without interference from the reader. The insert switch 2-2! will normally be' closed, and will be opened when it is desired to type manuallyan insert in The typewriter 296 is.

the data being transcribed; for; example, it is desired to type manually the nameandzade dress of the'person to whom the transcribedz copy is to be sent or any other data. whiplmwilt be of interest only to the recipient of the copy.

The detail construction of the reader I 00? is shown in Figs. 2 to 7, inclusive. The reader'comsprises the reader motor RM. which is suitably mounted within the housing; l2 andwhich. opcrates continuously as long as either the power switch 24 or power switch 224 is closed. The motor RM is at all times operatively connected by a.

suitable flexible drive belt 3|) with a. power shaft. 3|, the latter being mounted for. rotation within; suitable bearings 32 mounted within a. frame 33-: which is bolted to the base 34 of the reader.

The reader I00 also comprises; an operating; shaft 35 which is aligned with the power shaft 3| and is supported for rotation. within suitable bearings 35 carried by the reader frame 3.3.. The shaft 35 is the reader shaft which. was; men;- tioned hereinabove before the brief description of the several views. A clutch 31, under the control. of a clutch magnet CM,. is operable. to connect. and disconnect the reader shaft. 35' and the power shaft 3|. The reader shaft 35. effects the opera-- tion of the tape feeding and sensing means. A cycle of operation of the apparatus is. effected during each revolution of the shaft 35-; viz., the. tape H2 is fed or spaced a. distancesufilcient. to bring the next, recordin field. of the tape into sensing position, such next field is sensed to= determine the code designations therein, if any, and the typewriter is operated. in response to the sensing of the code designation. As. long. as. the shafts 3| and 35 are clutched together the cycles of operation are. repeated and the type-- writer continues to transcribe the data. recorded. in the tape being read.

In so far as the present. invention is concerned}. any suitable form of clutch may be. used. to connect the reader shaft 35 to the continuously operated power shaft 3|. The clutch. 31 which is shown, is well known to those skilled in this art, it being substantially the same as that. disclosed in the U. S. Patent No. 2,206,646, grantedJTuly 2, 940. If desired, reference maybe had to this patent for a complete showing of the structural details thereof. For the purposes of the, present disclosure, it is believed sufilcientto say that the clutch comprises a driving element in the form of a toothed wheel fixed to the end of the power shaft 3|, and a driven element in the form of a barrel 4| fixed to the reader shaft 3 5 and carrying a radially slidable-clutch pawl 42; The barrel 4| is formed with a diametrically disposed slot 43- within which the pawl 42 is slidably mounted. To the outer end of the pawl 42- is'fixed a tooth element 44 which, when the pawl 42 is moved radially inward, engages the toothed wheel 4| to provide the driving connection between the shafts 3| and 35. The pawl 42 is biased: i-n a clutch engaging direction. by a suitable spring mounted within the clutch barrel 41. A clutch releasing lever 45 also extends diametrically across the clutch barrel and at right angles to the slot 43 and is mounted for limited angular movement therein. The lever is provided with an outer extension 46 which, when intercepted and engaged by the outer end of one arm 41 of a rocking lever 48-, is moved to move the clutch pawl 42 radially outward against the force of the aforementioned spring inthe barrel 4 to-disengage the clutch.

The clutch parts are shown in Figs. 2 and 6' intheir declutched positionwhich. is the home or lever 48 is mounted on a stud SUcarried by a part of I the frame 33 and includes a second arm which carries at its outer end thearm'ature 52 of the clutch magnetCM. Whenthe'clutch magnet CM is energized, the lever 48 is rocked counter clockwise, as viewed in Fig. 6, which moves the outer end of the arm 41 upward-and thereby releases the outer extension 46 of the releasing lever 45, and the clutch spring within the clutch barrel 4! then moves the pawl 42 radially inward to engage the toothed wheel 40 in the manner explained above. When the clutch magnet CM is deener'gized, a tension sprin'g'53 rocks the lever 48 clockwise and moves the outer end 'of the arm 41 into the path of the outer extension 46 of the lever so'that the latter is engaged and moved to move the pawl outward to disengage the clutch.

In order to prevent reboundof the parts when the clutch is disengaged and in order to hold the operating shaft 35 in the home position, the clutch barrel 4| is also provided with an annular extension or collar 54 having a notch55 formed therein which, when the clutch is disengaged, receives the outer end of an arm 56 of a detent lever 51. The detent lever 51 is also pivoted on the stud 50 and includes another arm 58 which is connected to the armature 52 by means of the ten sion spring 53 previously mentioned. Thus, the

spring 53 serves the dual purpose of urging the arm 56 into engagement with the periphery of the collar 54 so thatyit will fit within the notch 55in home position, and to urge the arm 41 into position to intercept the extension 46 of the pawl releasing lever 45 andthereby declutch the parts.

As stated above, during the first partof each revolution of the operating shaft 35, the tapeis fed or spaced lengthwise to bring anew record ing field into sensing position. The tape feeding mechanism is shown more clearly in Figs. 2 and 4, and comprises a cam 60 mountedon the reader shaft .35 and cooperating with a rocking lever 6| pivotedon afixed stud 52 carried bythe frame 33 and comprising'a pair of arms 63 and 64. The

camifl and'lever 6| are shown in Fig. 4 in the therefrom and is'pivoted at its upper end by a, stud 61 with a second link 68. The link 68' is.

alsopivoted to a shaft 10 and servesto hold the link 66 in its upright position shown.

,Also plvotally connected on the stud 67 is a feed'pawl H which is held in operativejengage ment with a ratchet wheel 12 fixed to the shaft 1D, by means of a tension spring 13 connecting outer extending arms ofthe pawl H and the link 68. 'A detent I4 is pivotally supported by'a'fixed stud l5 and is held in engagement with the teeth of the ratchet wheel 52 by means of ,,a tension spring 16 and thereby serves to prevent reverse movement of the ratchet wheel I2 and shaft'll]. From the above; it is apparent that when'the clutch 31 is engaged to rotate the reader shaft and when the lever BI is first rocked counterclockwise by the cam 50, the. pawl II will be moved, downwardly thereby and will rotate the ratchet l2 ,andshaft 1,0 counterclockwise; and, whenthe cam 60 rocks the'lever 6| clockwisathe pawli'l llwillbe movedupward mes age en neer tooth'of thelratchet 12. 7

r The shaft 10 is the tape feed shaft and is'pr'os vided. with a .feed .wheel' 11 having. radially extendingpins' .18 which are adapted to engage the feedhdles H in the tape l0. Thus, when the feed shaft is partially rotated in the mannerjust described;'the tape is fed to the left as viewedin Figs. 2. and 3, a'distance' equal to the width of a recording field. The belt" which rotates the spool 16 shown in Fig. 1, is driven from a pulley l9 fixed to the tape feed shaft 10.

The me'chanism for successively sensing therecording fields ofthetape comprises six' sensing pins indicated, respectively, by thechara'cters SI to S6, inclusive. There is one pinfor caches the codehole positions and the pins are arranged in a single planeextending at righ angles tothe direction. of movement ofthe tape, and sotliat when-the tapecomes to rest at the end'Tofa fee-ding operation, the upper end of each pin?will be directly beneath its corresponding code hole position in the field'of the tapethen in position to be sensed. The pins are guided for'vertical movement. within aligned openings in" spaced guide blocks 83 and 8|, respectively, which are suitably fixed to the. frame 33. Aligned pairs of guide/openings are also provided in thetable l3 and in'the' gate 2| and they are aligned with corresponding openings inthe guide blocks so that during .a sensing operation each pin can be moved upward and through the tape when there is a hole in the code position in the tape corresponding to such pin. t r

The six'sensing'pins are supported and op'eratively connected, respectively, at their lower ends to six pairs of spring blade contacts indicated, respectively; by the characters CI 'to' QBJin'clu sive; Each pair of the contacts comprises an,

upper fixed blade 32 anda lower'movablespring blade 83 which extends outwardly beyond the end of its related fixed blade and is connected'at its outer end to the'lower end of its related sensing pin; The construction is such that th'eis'pring blades 83 constantly urge their 're'spectivecontacts upward into closed position andtlieir'related sensing-pins upward as'viewed in Figs. 3"

and '7; Betweensensing operations, the s'ix' 'sens ing pins are held in home position, the position shown'in Fig. 3, by the outerlateraljedge 84 of a vane 85, which edge extends across'ia'll of the pins and within .transversely'aligned notches 8% provided, respectively, in th sides'o fthe'pins; The vane 85 is, in effectga rocker arm pivotally supported snared 81 carried by the'frameQ33 and constantly 'urged to move in a clock'wise direction, as viewed in Fig. 3, by a tension spring 88. The vane B5Iis provided at its center with a depending arm 89 which carries at its low er-end a roller 90 held by the spring 88 in contactwlth the face of a cam 5| mounted on the reader shaft 35. When the roller '96 is in engagemeiit with the high point'cf the cam 9| the vane 85 is held in the position shown in Fig. 3 where the several sensing pins are held in their respective lower positions and the pairs of contacts f controlled thereby are held open.

After the tape has been spaced by the feeding mechanismlin the: manner previously described and has come to r'estwith' theinew'recordling field above the'sensing pins, the cam 9| will have rotated counterclockwise from the position shown in Fig; 3,94? of a revolution. .When the'shaft 35' has-rotated 114, thejroller 90 willrbegin to move finwardly'from the high point" of 1 the cam ego 7,011"

the typewriter are shown as terminating at the right-hand margin of Fig. 120. in plug socket connections, designated, respectively as Rl to R56, inclusive. ,The corresponding circuit wires:

in the typewriter terminate at the left-hand margin of Fig. 121) in plug socket connections TI to T56, inclusive. It is to be assumed that the plug sockets Rl to R56 are connected, respectively, to the plug sockets .TI to T56, inclusive, by the individual cable wires.

As stated above, thejrelay translator mechanism comprises the series of relays Ml to M6, inclusive, which, during eachcycle of operation of the reader, are energized singly or in combination, asaresult ofthe' sensing of code hole designations in the record tape. The relay translator shownis a well known mechanism which, in response to the selective energization of its relay magnets in the manner just stated, sets up a number of controlling circuit paths corresponding, respectively, to the code designations sensedq The relays Mi to M6, inclusive, control, respectively, the operation of, one'or more related transfer cont-acts which during each sensing cycle will be transferred, or left at normal position, so

that thecontacts may be connected in combinational series to condition the just mentioned controlling circuit paths. of relay Ml operates a pair of contacts Ml-l the armature of relay M2 operates two pairs of contacts M2I and,,M22; the armature of relay M3 operates four pairs of contacts M3-l to M3- 4, inclusive; the armature of relay. M4

operates eight contacts M4-| to M48, inclu-f sive; the armature of relay M5 operates sixte n contacts.M5| to M5|6, inclusive; and the armature of relay. M6 operates thirty-twocontacts M6-I to NIB-32, inclusive. In Fig. 12a, these various relay controlled transfer contacts are shown: in their upper or normal position, which is the position they occupy when their related operating relays are deenergized. When any translator relay is energized, all of its related contacts transfer to the lower position.

In Fig. 1211 the plug socket connections TI to T48, inclusive, are shown as connected, respectively, by individual circuit wires with the solenoids 230 which operatethe character and functional key levers of the typewriter previously described. As stated previously, a legend appears adjacent each solenoid indicating the typewriter character or function corresponding thereto.

In Figs. 12a and 126, all switches, solenoids, relays, contacts and associated parts are shown in the positions they normally occupy, with no tape under the sensing gate 2| (Fig. 1) and with both power switches 24 and 224 in open position. It is also noted that'a switch 324 and a switch 325 are shown in Fig. 1211 as being in open position.

' As will presently appear these switches 324 and 325 are provided for the purpose of selectively including and eliminating control of the reader operation by the unitary, timing mechanism 300. A source of alternating current is indicated in Fig. 12a by the lead wires 400 and 40 I.

As stated previously, both the reader motor RM and the typewriter motor TM are operated When either the power 24 or the power switch 224 is in closed position. One side of the motor RM ispermanently connected to the lead 400, and also oneside of the, motor TM is permanently connected to the lead 400 by a. wire 402, plug socketv connections -R56and T56, wire 403, and wire 404.- Upon closing of switch 24, the other side of the motor RM is connected thereby to the As shown, the armature other AG supply lead 401 by a wire 405, and th other side of the motor TM is connected to the supply lead 40I by a wire 406, plug socket connections T and R50 and wire 401. The closure of the switch 24 also energizes a rectifier transformer 408, oneside of the primary being permanently connected to the supply lead 400, and the other side being connected to the wire 405, and through the latter and switch 24 with the other supply wire 40].

With one side of the motors RM and TM and. transformer 408 being permanently connected to the lead 400 in the manner just explained, the closing of switch 224 also energizes the motors RM and TM and the transformer 408 as follows: from wire 40!, wire 409, plug socket connections R and T55, Wire 0, the switch 224, a wire 4! l, wire M2, and Wire 406, to the other side of the motor TM; and through wire 406, plug socket connections T50 and R50, the wires 401 and 405, to the other side .of the motor RM and the other side of the primaryof transformer 408.

With the transformer 408 energized in the manner just explained, alternating current is supplied to the inputterminals of the rectifier M5. The positive and negative D. C. output terminals of rectifier-4 I 5 are connected, respectively, to the plus bus M6 and to the minus bus M1. The opposite sides of the coil of a reader relay 4l8 are permanently connected with the plus bus 4 I 6 and. the minus bus 4", so that as long as the rectifier is supplied with alternating current, the relay 418 remains energized. When the relay M8 is thus energized, the armature 419 thereof connects the minus bus 1 to each of wires 42|,422, 423, 424, 425, and 426, which are respectively con-' nected to the. return sides of the six translator relays Ml to M6, inclusive.

The operation of the apparatus will first be described with the. control by the unitary timing mechanism 300 selectively eliminated. In order to operate the apparatus without control by the mechanism 300, the switch 324 is closed and the switch 325 is open. It will be assumed first that V the switches 324 and 325 are in these positions.

With a record tape properly positioned under the gate 2| in the reader I00, the contacts 96 are closed by the pin 94 and the apparatus is ready for successively reading and transcribing "the code designations in the tape onto the record sheet 22! in the typewriter. Thetape sensing and feeding operation is started by depressingv either the reader start switch 25 or the-typewriter start switch 225. The reader start switch 25 is provided with two pairs of spring blade contacts 421' through the wire 430, contacts 421, a wire 43!,

plug socket connections R53 and. T53, awire 432, the normally closed insert switch 221, a wire 433, plug socket connections T5] and RSI, a wire 434, normally closed pick-up contacts 435 of a master control relay 436, a wire 431 to one side of a main coil 438 of such relay 436; and, from the coil 438, through wire 439, a wire 440, the now closed contacts 96, and a wire 44! to the minus bus 1. When the master control 436 relay is thus energized, the armature thereof moves to #the right and therebyopens the pick-up contacts 435 andcl'oses a;pair of holding contacts "443, the latter being connected directly to the plus bus Why a wire 444'. 'The contacts 4'35and 443 are of=the overlapping'type, that is, the holding contacts 443 make before the pick-up contacts 435 break. with the holding cont-acts 443 closed, direct current will flow through the holding circuit for the main coil 438 which is traced as follows: from the plus bus 416, through the wire 444, contacts 44-3, wire 431, to the -coil 438; and, *fromthelatter, through wire 439, wire 440,-contacts '96, and -wire-44'1,'to the minus bus 4-17.

Contacts 445 also close when master control relay 436 is energized and'they thereby-condition an energizing circuit for the clutch magnet CM. This "conditioned clutch magnet control circuit is established when the start switchcontacts 428 are again closed 'when the operator releases the start switch 25. The clutch magnet circuit "is traced asfollows: from the D. C.positivebus 4115 through theplug socket connections R54 and T54, a wire 4'46, normally closed contacts 250 which are under the control of elements of the typewriter, a "wire 44'1, normally closed contacts i which are also 'under the control of elements of the typewriter and will be explained hereinafter, a wire 4'48, normally .closed contacts 449 of the typewriter start switch 225, Wire 450, plug socket connections T52 and R52, wire 451, the now closed contacts 445 of the master control relay 436, a wire 4.53, the now closed contacts 428 of the start switch .25, wire 454, the clutch magnet CM, and from the latter through a wire 455, the control switch 324 .now Closed so as to eliminate control by the timing mechanism 309, a wire 4%, the Wire 4411, the now closed contacts 95, .and wire 441 to the minus bus 411. The clutch magnet circuit just traced directly controls the operation of the reader in the manner previously explained; i. s. when the clutch magnet CM is energized by the closing of this circuit, the operating shaft of the reader is connected by the clutch 31 .to the power shaft 31 and the successive cyclic tape feeding and sensing operations will begin and will continue at a rate determined by the designed speed of the power shaft until the clutch magnet is deenergized by the opening of any of 'the now closed contacts in its control circuit.

The typewriter start switch '225 is connected in parallel with the start switch 25, so that the operation of the apparatus may be started by depressing and releasing the switch 225 in the same manner as just described in connection with the switch 25. As shown, the switch 225 is provided with two pairs of spring blade contacts which are the normally closed contacts 449 mentioned above, and a normally open pair of contacts 458. One contact of the pair of contacts 458 is permanentlyconnected to the D. C. plus bus 415 through the wire 4'46 and .plug socket connections T54 and R54. The other contact of the pair of contacts 458 is connected by a wire 459 and a wire 450 with the normally closedinser-t switch 221 which, as explained previously in connection with switch 25, is connected to the D. C. minus bus 411 through the wire 433, plug socket connections T51 and R51, wire 434, picl -up :convtacts 435 of the master control relay 435, wire 4.31, coil 438, wire 439, wire 449, contacts 98, and wire 441. Thus, with the apparatus at rest, by depressing the switch 225 to close its-contacts 458, and open the contacts 449, a flow path ior direct current is established through the pick-up contacts 435 and coil 438 of the master control relay 436, and the latter, when energized, -will close its holding contacts 443 and remain energized by the holding circuit established thereby which was previously traced. As explained above, the contacts ME-are closed by the energizing of relay 4% and theclutch magnet circuit is conditioned thereby. When the start switch 225 is released, its contacts 4453 close and the conditioned energizing circuit for the clutch magnet CM is thereby established.

As described previously herein, when the reader shaft '35 commences to rotate, due to the energizing'of the clutch magnet CM and the re- 'sulting "engagement of clutch 31, the tape t!) is first spaced to move a record field into sensing position which is directly above the sensing pins S1 to 'SB,'inc1usive, and the field is sensedby the pins to determine the code hole designation therein. As an example let it be assumed that the record field being sensed bears the code hole designation for the letter character Y, which, as shown in Fig. 13,-comprises code holes inpositions 1, 3, and'5. As shown in Fig. '7, and as previously explained, the sensing of the code hole designation for the letter Y will result in the sensing pins S1, S3, and S5 moving upward through the code holes in the tape to close contacts 'C1, C3, and 0-5, respectively. The contacts C1, C3, and C5'will close at approximately 130 of the revolution of shaft 35 and will remain "closed until 325, and the D. C. common contacts i134 are closed by the cam 132 at 142 and are opened at 311. With the contacts "C1, C3, and

' C5 closed, and "with thel). C. common contacts 1-04 closed, direct current will flow from the D. 0. positive bus 416 through contacts 1&4, the contacts C1, C3, and'CS in parallel, and through wires 461, 463, and 4% to translator relay magnets hi1, M3, and 1W5, respectively, and from the latter through wires 421, 423, and 425, respectively, to the D. C. minus bus 41 '1. With the relay magnets M1, M3, and M5 thus energized, their related contacts are transferred to their respective lower positions. As the relays M2, .M4, and "M6 remain deenergized, their related transfer contacts will remain in their normal upper positions.

'With the transfer contacts of the translator in the position .just stated, and when the cam on the reader shaft 35 closes the A. C. common contacts 1118 at .170" of the revolution of shaft 35, alternating current will flow through the circuit path established by the translator contacts to the solenoid 238 controlling the key lever 228 for the letter f on the typewriter, and, thereby, .eiliect .the operation of :the related type bar in the manner previously explained. The established circuit path is traceable as follows: from the A. C. supply lead 4013, contacts 138 now closed, a wire 461, contacts M-11 .in the lower position, a wire 4E, contacts M2'2 in the position shown, .a wire 469,00ntacts M3-3 in the lower position, .a wire 4-19, contacts M4'B in the .position shown, a wire M1,-contacts M5-1'1 in the lower position, .a wire 412, contacts ME-EE in the position shown, a wire 4 13 the .plug socket connections R33 and T33, a wire 43-4, solenoid 230 for actuating the hey lever corresponding to the letter character Y, a wire 4'15, and if the power switch 24 is closed, through the wires M2 and 411$,plug socket connections T58 and R50, the wire 4fl'1',switch 2 4 to the A. C. supply wire 401. .If instead, the

switch 2:24 is :closed, the circuit will include the 1 wire .4I I, switch224, wire 4I0, plugsockets T55 and R55, and wire 409. i

From the foregoing it will be understood that if the clutch magnet CM remains energized, and the contacts 96 are closed by the tape I0 at the reading station 20, the cycles of operation of the apparatus will be repeated'at the designed speed of the shaft 3 I. During each such cycle of operation, the tape will first be spaced to bring the new record field into sensing position, and such recs ord field will then be sensed to determine the code designation therein in the manner previously described. If the fieldsensed bears a character code designation, a space code designation, a shift code designation or a shift release code designa tion, the translator relays will be operated to provide an A. C. controlling circuit path through the related solenoids to actuate the related key lever in the same manner as just explained in connec tion with the sensing of the code designation for the letter character Y.

As is disclosed fully in the aforementioned copending application of Tholstrup, when the code designation. is sensed which represents a functional operation of the typewriter requiring a longer-than-normal time for its completion, provision is made for stopping the cyclic sensing operation of the reader when such functional operations are being effected by the typewriter and for resuming the sensing operations upon a completion'of such functional operation. Examples of such functional operations requiring a longer-than-normal time for their completion are carriage return, tabulating, and back-space;

'From an examination of Fig. 121), it will be noted that each of the key lever actuating solenoids 238 for effecting these three last-mentioned functional operations is connected to a circuit wire 411, and that the latter is in turn connected through a wire 418, plug socket connections T49 and R48 and the wire 419 with one input terminal of a rectifier 480. The other input terminal of the rectifier 480 is connected by a wire 48L the wire 401 and switch, 24 with the.A..C'. supply wire 40 I. If the switch 224 is closed instead of switch 24 such other input terminal of rectifier 480 is connected to supply wire 40I through plug 7 sockets R and T50, wire 406, wire 4I2, wire 4| I,

switch 224, wire 0, plug sockets T and R55, and wire 409.

Thus, when the code designation corresponding to either the carriage return, tabulating or back space operation is sensed, and the translator is adjusted thereby to condition a controllingcircuit through the solenoid 230 corresponding to the sensed code designation, the closing of the A. C. common contacts I08 will energize such corre sponding solenoid 230 and will connect the input terminals of rectifier 480 across the A. C. supply line. One D. C. output terminal of the rectifier 480 is connected by a wire 482, relay contacts 483 and wire 484 with one side of a bucking'coil 485 of relay 436, and the'other side of the coil 485 is connected by a wire 486 with the other D. C. out put terminal of the rectifier. With the relay 436 energized, the contacts 483 are closed. Consequently, the just described closing of A. C. common contacts I08 will result in the energizing of bucking coil 485. The coils 485 and 436 are oppo-. sitely wound, and the coil 485 is of sufficient strength to overcome the coil 438 and cause relay 436 to drop out and thereby open its holding contacts 443. The contacts 483 also drop out and break the circuit. through the bucking coil 485. The contacts 445 in the clutch magnet circuit also I open to deenergize-the clutch magnet CM and thereby stop further sensing operations; The

V pick-up contacts 435 close, but the main 'coil'430 tacts 445 and 25I.

cannot be energized again until other normally 1 magnet circuit, the latter circuit will now be open at two points, viz., the contacts 445 and 250. 7

When the contacts 252 close, they establish a pick-up circuit for the maincoil 438 of relay 436 through the now closed pick-up contacts 435. V This pick-up circuit is as follows: from the plus bar'4 I6, plug sockets R54 and T54, wire 446, contacts 252, wire 460, insert switch 221, wire 433, sockets T5I and R5I, wire 434, pick-up contacts 435, wire 431, main coil 438, wire 439, wire 440, contacts 96, and wire I to the minus bus M1. The relay 438 is thereby again picked up and is held by its hold contacts 443 as before and its contacts 445 in the clutch magnet, circuit, close, but the'latter circuit is not closed as typewriter contacts 250 are still open. When the carriage return operation is completed and the contacts 250 again close the clutch magnet CM is energized and the cyclic sensingoperations of the. reader continue as before.

When the typewriter begins a tabulating operation the contacts 25I in the clutch magnet cirlcuit are opened by an element of the typewriter and contacts 254 are closed. Thus, when the code designation representing a tabulating operation is sensed, the typewriter carriage is tabulated and the master control relay 436 is dropped out by the energizing of the bucking coil 480, and the clutch magnet circuit is opened both by con- The closing ofcontacts 254 connects the wires 446 and 460, the same as contacts 252, and they thereby establish the pick-up circuit which was traced above for master control relay 436. The relay'436 is held energized by its contacts 443, and when the tabulating operation is completed and the contacts 25I again closed, the clutch magnet circuit is again established and cyclic reading operations are resumed,

When a back-space code designation is sensed,

the typewriter is caused to back space and the master relay 436 is dropped out due to the energizing of the bucking coil 480, and the clutch magnet circuit opened by contacts 445, as before. I

However, as a back space'operation only requires a relatively short period of time to be completed, the relay 436 is immediately picked up again and held and the clutch magnet circuit restored by its contacts 445. The latter is effected by con-' tacts255 connecting wires 446 and 460 and which are closed by a typewriter element which moves as a result of a back-space operation. I

The operation of the reader I00 may also be manually stopped by depressing' either stop the other side of switch 226 is connected to the j other supply wire! through the wires 41! and,

418, plug sockets T49 and R49, the ire 4119, the rectifier 480 and the wires 48] and 407. Thus. when either switch 26 or switch 226 is depressed the rectifier is connected across the A. C. supply line and the bucking coil is thereby energized to drop out the master control relay 436 and thereby open the clutch magnet circuit and stop the reader. Reading operations can then be resumed only by depressin the start switch 25 or 225 to pick up the master relay again, as previously described.

As explained at the outset, letter writin apparatus, such as described hereinabove, is sometimes used in connection with, or to control, auxiliary apparatus which often requires a longer period of time to complete one operation than is provided during a cycle of operation of the reader shaft when the latter is driven continuously at the designed speed of the power shaft 3|. As stated, one example of such an auxiliary apparatus would be a tape punch which operates, when each code designation in tape i is sensed by the reader I00 and the typewriter 203 o erated as a result thereof, to record in a second tape a code designation which corresponds to the sensed code designation. The code designation recorded in the second tape may be in either the same code or in a different code from the code of the sensed designation. In accordance with the present invention, a record controlled printing apparatus is provided which for simple letter writing operations may operate in the usual manner and at its designed maximum speed and which may be readily adjusted by the operator when desired, to operate at some predetermined reduced speed which is slow enough to permit the controlled synchronous operation of auxiliary apparatus such as a tape punch. This advantageous result is accomplished in the illustrative embodiment by the unitary timin mechanism 300 which may be included or eliminated, at the selection of the operator, ,as a part of the means for controlling the operation of the reader {.00.

The timing mechanism .300 is shown structurally in Figs. 1, 8, 9, 10, and 11, and is shown diagrammatically in Fig. 12a. As shown in Figs. 8 and 9 the mechanism 300 is suitably mounted upon a bracket plate 302 which is secured by screws 303 to the base plate 34 of the reader I00, and the mechanism comprises a synchronous motor unit 305, a shaft 305 driven by the motor at a predetermined time rate, a cam .30! fixed by a set screw 308 on to the shaft 306 and having formed in its periphery a predetermined number of switch operating recesses 309, and a switch 3l0 having an operating arm 3]! pivotally supported at one end by a pin 3!,2 carried by a fixed bracket plate 313, za-nd'the arm 3 carrying .a roller 3 at its other end which roller is spring urged into contact withthe periphery of the cam 301. The switch 310 may be of any suitable construction and is operated by the arm 3H .engaging a pin 31.5 and in such a manner that when the roller 3 occupies a depression 309 of the cam 30-! the switch .3;-|.0 is closed and when the roller engages the high cylindrical surface .316 of the cam'the switch 310 is held open. While theswitch 310 may be of any suitable construction so longas it .operatesin the manner indicated and whilehis-diagrammatically represented in '1'2aas a pair of simple spring :blade contacts, the actual switchstructure disclosed in Figs. 8 and :9 will bereadily recognized by those skilled in "-thisxartias ebeingaone which is known commercially as a micro-switch.

As a typical example itis assumed that the motor unit 385 shown, is arr-A. C. synchronous motor operating at 1800' R. P. M. and that it has a built+in reduction gear unit (not shown) which drives the cam shaft 306 .at the reduced speed of 60 R. M. or 1 R. P, The cam 337 is shown in Fig. 8 as being formed with five equally spaced depressions 309.2 Thus, vforeach revolution of the earn 307, the switch 310 is closed five times, or once each one fi'fthof a; second. In Fig. 10 is shown a cam 301a havingsfour equally spaced recesses 309a andFig. 11 shows a cam 301D having two diametrically arranged recesses 30%. When desired, the cam 331 of Figs. 8 and 9 can be readily removed by looseningthe' set screw 398 and either the cam 301a or 30112 substituted in lieu thereof. Withthe cam 301a on the shaft 303 the switch alt willbe operated four times for each reyolut-ion of the shaft 303 which is four times each second, or once each one fourth of a second. With the cam 30'Ib on the shaft 303 the switch 3,10 will bebperated twice each second or once each one half of a second.

By way of example, it is also assumed'that in the illustrative embodiment, the motor RM and the belt drive connection between the motor RM and the shaft 3] is designed to provide a speed Of shaft 3! Which is on the order of eight nd on th rd revolutions per s co d /3 S.). Thus, when clutch 131 .is continually enease t e reader: shaft 35-:wi11 rotate at 8 /3 R P. S. to provide 8%3' readin y s p s 0nd or one readingcycle each twelve hundredths (.12) cfas cc d- Refe ri g again tcl 'iss. Band 9 it is noted that an outlet 3| 3 is inopnted-on the bracket plate 332 and serves to connect the A. C. supply wires to the timing motor .unit 305.- A suitable power switc 325.1 el e-mounted on the plate 302 and controls theflow. of tothe motor unit 305. Two pai s of plne s ck ts. 320a and .3201) are also mounted on the plate 302 andserve as a means for connecting the micro-switch? into the reader control circuits. Thetirningmotor unit 305, switch 310,. switch 325. and. the two pairs of plug sockets 320a and 3201) a e Shown diagrammatic lly in Fig. 12a. 1

e -.cc.a i c o erat n relationsh p between the timing mechanism 300 and the other elements of the illustrati-ye embodiment of recordntrcl cd p nt ng a p atus ;.f.c ming the sub- J ma ter o theprcscntinvention, Will be pparent froman examination .of Figs. 12a and 1 b- O cseck ici the Pair of p us s k ts 32 11 is shown as connected by a wire 4.911 with the wire 455 and the other socket oi the pair 3200. is connecteci'by a Wire 43] with the wire 456. The A. supply wire-unis shown as connected directly to one side of timing motor unit 305, and he other side of thetiming motor is shown as connected to the .otherA; C. supply wire Mil through the switch 325, the wire 405, and then either through power switch 24"or' 224 in the manner previously explained. With this explanation it will lee-apparent that with the switch 32.4 open, the contacts ot-the cam controlled switch .310 will be corinectedin the energizing circuit tor the :cluitch magnet- :CM, and with the switch 325 .closed' the timing :motor 305 will operate to Iopen the -:clutch.-magnet circuit when the roller 3 engages the high cylindrical portions 3116 of the .earn '300 and will -close the'clutch'magnet ctrcuitieach time "the roller L3H- enters a depression 3109101" ithe cam] With ithe cam 30! hayingfire --r ecesses, mounted on shaft 306, the

21 vice; and means operable at a predetermined time rate independently of said cyclically operable mechanism to effect operation of said circuit closing device to close and then open said circuit at predetermined intervals of time.

'7. In apparatus for printing, on a copy sheet, data which has been recorded as code designations on a record sheet, the combination of cyclically operable mechanism for successively sensing said code designations, there being one sensing operation for each operating cycle; printing means for printing the data on a copy sheet; means acting in response to the sensing of each code designation for effecting an operation of said printing means in accordance with said sensed designation; an electro mechanical device operable when energized to eifect one cycle of operation of said mechanism; timing means including an A. C. motor operating continuously at a time rate determined by the frequency of the current supply, a cam shaft driven by said motor, and a cam on said shaft formed with switch actuating portions; and means for energizing said electro mechanical device comprising an electrical circuit and a switch engageable by said portions on said cam for closing said circuit.

8. In apparatus for printing on a copy sheet data which has been recorded as code designations on a record sheet, the combination of cyclically operable reader mechanism including a rotatable reader shaft, each revolution thereof corresponding to an operating cycle, means operated by said reader shaft during each revolution for spacing said record sheet to bring a code designation into a sensing position, and means operated by said reader shaft during each revolution for sensing a code designation in said sensing position; printing means for printing the data on a copy sheet; means acting in response to the sensing of a code designation and controlled by said reader shaft for operating said printing mechanism in accordance with the sensed code designation; a continuously rotating power shaft; a onerevolution clutch operable when engaged to connect said power and reader shafts for one revolution and then become disengaged; timing means operable at a predetermined time rate independently of said cyclically operable reader mechanism; and means responsive to said timing means for effecting engagement of said clutch at predetermined time intervals.

9. In apparatus for printing on a copy sheet data which has been recorded as code designations on a record sheet, the combination of cyclically operable reader mechanism including a rotatable reader shaft, each revolution thereof corresponding to an operating cycle, means operated by said reader shaft during each revolution for spacing said record sheet to bring a code designation into a sensing position, and means operated by said reader shaft during each revolution for sensing a code designation in said sensing position; printing means for printing the data on a copy sheet; means acting in response to the sensing of a code designation and controlled by said reader shaft for operating said printing mechanism in accordance with the sensed code designation; a continuously rotating power shaft; a one-revolution clutch operable when engaged to connect said power and reader shafts for one revolution and then become disengaged; an electro magnetic device operable when energized to effect engagement of said clutch; an energizing circuit for said device including a source of electricity and a switch for closing said circuit; timing means operable at a predetermined time rate independently of said cyclically operable reader mechanism; and means responsive to said timing means for momentarily closing said switch at predetermined time intervals.

10. In apparatus for printing on a copy sheet data which has been recorded as code designations on a record sheet, the combination of cyclically operable reader mechanism including a rotatable reader shaft, each revolution thereof corresponding to an operating cycle, means operated by said reader shaft during each revolution for spacing said record sheet to bring a code designation into a sensing position, and means operated by said reader shaft during each revolution for sensing a code designation in said sensin position; printing means for printing the data on a copy sheet; means acting in response to the sensing of a code designation and controlled by said reader shaft for operating said printing mechanism in accordance with the sensed code designation; a continuously rotating power shaft; a onerevolution clutch operable when engaged to connect said power and reader shafts for one revolution and then become disen aged; an electro magnetic device operable when energized to effect engagement of said clutch; an energizing circuit for said device including a source of electricity and a switch for closing said circuit; and timing means for operating said switch comprising an A. C. motor operating continuously at a time rate determined by the frequency of the current supply, a shaft driven by said motor, and a cam fixed to said shaft and having switch actuating portions thereon operable to effect momentary closing of said switch.

JOHN A. SKINNER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,292,944 Wright Jan. 28, 1919 1,456,503 I-Ieising May 29, 1923 2,282,107 Watson, Jr. May 5, 1942 2,290,626 Bosomworth n July 21, 1942 2,378,371 Tholstrup June 12, 1945 

